Catalyst and process for producing catalyst

Abstract

A cobalt/aluminum catalyst for the polymerization of polyesters of terephthalic acid and an ethylene glycol, and a process for the preparation of such catalysts.

What is claimed is: 
     
       1. A process for the production of poly(ethylene terephthalate) polymer which comprises combining a polymerization catalyst formed by combining a cobalt salt that is soluble in ethylene glycol and aluminum compound selected from the group consisting of aluminum chloride, aluminum hydroxide, aluminum acetate, and aluminum hydroxychloride in ethylene glycol, where the mole ratio of aluminum to cobalt is 0.25 to 1 to 16 to 1, with terephthalic acid and ethylene glycol, or low molecular weight poly(ethylene terephthalate) polymer or oligomer, where the concentration of cobalt in the thus formed mixture is in the range of about 10 to 100 parts per million parts of the mixture and polymerizing the mixture. 
     
     
       2. The process of claim 1 in which the cobalt salt is cobaltous acetate tetrahydrate. 
     
     
       3. The process of claim 1 in which the cobalt salt is selected from the group consisting of cobaltous acetate tetrahydrate, cobaltous nitrate, cobaltous chloride, cobalt acetylacetonate, cobalt naphthenate, cobalt hydroxide, and cobalt salicyl salicylate. 
     
     
       4. The process of claim 1 where sodium isophthalic acid-5-sulfonate glycol ester or trimellitic acid glycol ester is in the mixture to be polymerized. 
     
     
       5. A process for the production of poly(ethylene terephthalate) polymer which comprises combining a catalyst solution in ethylene glycol having an aluminum to cobalt mole ratio in the range of 0.25 to 1 to 16 to 1 and a chlorine to aluminum mole ratio in the range of 0 to 3, with terephthalic acid and ethylene glycol, or low molecular weight poly(ethylene terephthalate) polymer or oligomer, where the concentration of cobalt in the thus formed mixture is in the range of about 10 to 100 parts per million parts of the mixture and polymerizing the mixture.